Aviruth Wongbuddhapitak knows the dangers of unhedged currency exposure as well as anyone. The Siam Cement Public Company, of which he is vice president in charge of corporate finance and administration, went into the Asian economic crisis with around $5 billion of foreign borrowings, $4.2 billion of which was in US dollars. The subsequent devaluation of the Thai baht from Bt25 to the dollar to Bt40 wiped out around Bt60 billion $1.44 billion of shareholders equity.